W6XAO/KTSL/KNXT - Los Angeles

One of the most interesting stories in the history of early television
is that of Don Lee Broadcasting. Don Lee was a Cadillac dealer in Los
Angeles who entered the broadcasting business in 1926 with the purchase
of a radio station. In November, 1930, Don Lee engaged
the services of 24-year-old Harry R. Lubcke, B.S., University of
California, an electrical engineer, and gave him the title of Director
of Television of the Don Lee Broadcasting, and applied for a
construction permit for the first television station on the west coast,
W6XAO.

In 1931
Lee obtained a license for W6XS, which broadcast on a frequency of 2.1-2.2
mHz, using a mechanical camera that worked only with film. The picture
had 80 lines and 15 frames per second.
Since there
were few commercially available TV receivers at the time, Lubcke prepared
and distributed plans for construction of
mechanical receiving sets to many amateurs in the area of Los
Angeles. W6XS also broadcast on 2.75-2.85 mHz at some time before it went off the air in 1935. Here is a letter responding to a viewer of W6XS.

On December 23,
1931, W6XAO went on the air from the eighth-floor transmitter at Seventh
and Bixel streets, Los Angeles, at 44 1/2 megacycles, to broadcast one
hour daily except Sundays. This was one of the first VHF
stations to go on the air in the United States. W6XAO broadcast the same
80 line picture as W6XS.

Here is a description of the station from the
book "The Great Television Race" by Joseph H. Udelson:

In the Los Angeles area, Don Lee, who owned several California
radio outlets and headed a regional broadcast network, began
operating W6XS near Gardena in 1931, on the 2100-2200-kHz. channel.
In the spring of 1932 the station was moved to the Don Lee
Broadcasting System headquarters at 7th and Bixel, in Los Angeles,
where in December this video facility, operating in synchronization
with radio station KHJ, initiated a regular telecasting schedule from
6:00 to 7:00 p.m. Using a 1000 watt transmitter, an 80-line picture,
20 frames per second, was telecast. The programming consisted of
filmed action and closups of motion picture stars.

In the early 30s Lubcke started experimenting with electronic
television. By 1932 he had developed a CRT receiver with self
synchronization. . Because Los Angeles had both 50 and 60 Hz electric
power, and to facilitate use of CRT receivers, synchronizing pulses were
included in the video signal.

In 1932 he demonstrated television reception in an airplane.

In 1933 W6XAO, using "rapid process" film development, telecast news
footage of the 1933 Long Beach earthquake to L.A. viewers. This is the
first documented evidence of television news coverage. Who knows what
the received images looked like on the mechanical sets of the era.

March 10, 1933. W6XAO telecasts the first motion picture ever presented
on television. "The Crooked Circle". Perhaps 5 L.A. area television
receivers received the broadcast.

W2XS and W6AXO broadcast
the same 80 line images until 1936, when W6XS went off the air.

On June
4, 1936 W6XAO began a month-long
public demonstration of its new system, using 300 lines and 24 frames per second, and in 1937 W6XAO published instructions for building receivers for their signal. It is likely that only a handful were made.

The camera was a mechanical flying spot scanner type. One source
describes it having "some sort of
sine wave vibrating mirror and a Nipkow disk", while the article by F. Alton Everest describes a camera with a
large disk. Only
filmed material was telecast. Another article in the Los Angeles Times describes the advances made in
television, including at W6XAO.

From the above information, we can conclude that the camera worked as
follows: The disk spun at 3600 rpm, or 60 rps. To get the rate of 7200
lines per second (24 fps x 300), 120 holes would be required in the
disk. As the article says, the holes were all the same distance from the
center of the disk. It is not possible to determine the diameter of the
disk from the photo, but since it was driven by a 7 1/2 hp motor it must
have been quite large. Assuming a disk diameter of 6 feet, the
circumference would have been 226 inches. With 120 holes, the holes
would have been been 1.88 inches apart. The article says that the holes
were #80, which are .0135 inches in diameter. That would allow about 135
hole diameters in the 1.88 inch space, which would roughly translate
into the horizontal resolution of the camera. The article mentions that
the resolution was improved by aiming the light through the holes at an
angle. The screen shots look like about 150 line resolution.

Peter Yanczer commented on the above:

If it were 6 feet...
think about it. The disk circumference of about 19 feet would be
rotating 24 times per sec., therefore moving at about 450 feet per
sec. This is a little over 300 miles an hour. This gives one an
idea of the windage there would be. No doubt this would require an
evacuated housing, able to resist the atmospheric pressure on two
6 foot+ diameter surfaces. Air pressure is around a ton per square
foot, so you're looking at about 60 tons total on the housing.
Maybe I screwed up here? But I wouldn't go this route.

It was common practice on cameras to use smaller disks,
operating at higher than normal speeds in evacuated housings. if
you double the disk speed, the spacing between the holes doubles.
On 240L/25P, using a drum, Baird was running them as high as 6000
RPM. The same principal would apply to scanning disks.As for how Lubeck accomplished it, Possibly he also had some
optical techniques as well. There are ways.

I also wonder
about this business of running the light source on a slant to
improve resolution. With a scanning disk, that to me seems to
present problems. Yes, I have to wonder.

Actually, the disk would be rotating at 60 times per
second, making the speed at the edge about 1150 fps, approaching the
speed of sound.

DuMont and RCA Iconoscope cameras were obtained in late 1938 or early 1939, and
the standard was changed to 441 lines and 30 frames per second, in line
with the RCA system. In 1941 the station changed to 525 lines, and broadcast through World War Two with a limited schedule to
the handful of sets in the area.

An early Don Lee camera

W6XAO claims to have broadcast the first soap opera, on April 15, 1938,
called "Vine Street".

1939 telecast from the swimming pool located at the new W6XAO
studios/transmitter situated on Mt. Lee atop the Hollywood Hills

W6XYZ claimed that their 1943 remote telecast was the first on the west coast. However, W6XAO was actually first
with a live
telecast of the Tournament of Roses Parade on January 1, 1940.

Telecast from about 1939. The camera was made by RCA.

Rear view of Don Lee camera (ca 1939)

The RCA Iconoscope camera in 1942

This picture is allegedly of the first television commercial on the west
coast. The photo has a handwritten date of 1935 on it, but it must be
from 1939-41, the period during which W6XAO had the RCA camera shown in
the photo above this and in this photo. In the picture is Burton
Pfeiffer, making a television commercial for Kenwood Blankets.

The caption on this picture reads "The
internationally noted theatrical producer Max Reinhardt, is shown as
he made his television debut Nov 9 (1939). He is shown with Ann Lee,
an actress, when the producer and his company appeared in scenes
from "On Human Bondage" telecast from the Thomas S. Lee station,
W6XAO, only television station in the west."

California, Magazine of the Pacific, June 1939

Courtesy of Steve Dichter

The postmark is Sept. 25, 1939, and says "Betty
Jane Rhodes, First Lady of Television"

Late 30s test pattern

1944 Los Angeles phone listing

Courtesy of Steve Dichter

1939 Plans for Studio and Transmitter Building.
This building was never constructed.

The W6XAO antenna with building
housing transmitter and studio on Mt. Lee in 1941

Courtesy of Steve Dichter

Mt. Lee today

Courtesy of Steve Dichter

1942 advertisement

Some time after 1942 the station acquired RCA orthicon cameras. The photographs below are stereo slides taken some time between 1943 and 1945:

Putting on makeup

Interioir of the orthicon camera

In the studio

The microphone boom

The tower, with the transmitting antenna at the top

Watching programming on a TRK-12

The orthicon camera in 1945

Courtesy of Steve Dichter

A novelty program, "Ilustration Please", adaped from radio, was televised in 1944

Paintings from the United Seaman's Service Art Exhibit televised in 1944

Marilyn Monroe ?

Courtesy of Richard Diehl

On May 6, 1948, the station was granted full
commercial status. On becoming a full commercial operation the station
adopted the call letters KTSL-TV. Here is an article about remote pickups done by KTSL. It was acquired by the Columbia
Broadcasting System January 1, 1951, and ten months later, the call
letters were changed to KNXT to coincide with CBS Radio Station KNX. Here are pictures of KNXT's transmitter facility on Mt. Wilson, probably from the early 50s.